/*
 * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ScrollTypes_h
#define ScrollTypes_h

#include "wtf/Assertions.h"

namespace blink {

enum ScrollDirection {
    ScrollUpIgnoringWritingMode,
    ScrollDownIgnoringWritingMode,
    ScrollLeftIgnoringWritingMode,
    ScrollRightIgnoringWritingMode,

    ScrollBlockDirectionBackward,
    ScrollBlockDirectionForward,
    ScrollInlineDirectionBackward,
    ScrollInlineDirectionForward
};

enum ScrollDirectionPhysical {
    ScrollUp,
    ScrollDown,
    ScrollLeft,
    ScrollRight
};

enum ScrollType {
    UserScroll,
    ProgrammaticScroll,
    CompositorScroll
};

// Convert logical scroll direction to physical. Physical scroll directions are unaffected.
inline ScrollDirectionPhysical toPhysicalDirection(ScrollDirection direction, bool isVertical, bool isFlipped)
{
    switch (direction) {
    case ScrollBlockDirectionBackward: {
        if (isVertical) {
            if (!isFlipped)
                return ScrollUp;
            return ScrollDown;
        }
        if (!isFlipped)
            return ScrollLeft;
        return ScrollRight;
    }
    case ScrollBlockDirectionForward: {
        if (isVertical) {
            if (!isFlipped)
                return ScrollDown;
            return ScrollUp;
        }
        if (!isFlipped)
            return ScrollRight;
        return ScrollLeft;
    }
    case ScrollInlineDirectionBackward: {
        if (isVertical) {
            if (!isFlipped)
                return ScrollLeft;
            return ScrollRight;
        }
        if (!isFlipped)
            return ScrollUp;
        return ScrollDown;
    }
    case ScrollInlineDirectionForward: {
        if (isVertical) {
            if (!isFlipped)
                return ScrollRight;
            return ScrollLeft;
        }
        if (!isFlipped)
            return ScrollDown;
        return ScrollUp;
    }
    // Direction is already physical
    case ScrollUpIgnoringWritingMode:
        return ScrollUp;
    case ScrollDownIgnoringWritingMode:
        return ScrollDown;
    case ScrollLeftIgnoringWritingMode:
        return ScrollLeft;
    case ScrollRightIgnoringWritingMode:
        return ScrollRight;
    default:
        ASSERT_NOT_REACHED();
        break;
    }
    return ScrollUp;
}

inline ScrollDirection toScrollDirection(ScrollDirectionPhysical direction)
{
    switch (direction) {
    case ScrollUp:
        return ScrollUpIgnoringWritingMode;
    case ScrollDown:
        return ScrollDownIgnoringWritingMode;
    case ScrollLeft:
        return ScrollLeftIgnoringWritingMode;
    case ScrollRight:
        return ScrollRightIgnoringWritingMode;
    default:
        ASSERT_NOT_REACHED();
        break;
    }
    return ScrollUpIgnoringWritingMode;
}

enum ScrollGranularity {
    ScrollByLine,
    ScrollByPage,
    ScrollByDocument,
    ScrollByPixel,
    ScrollByPrecisePixel
};

enum ScrollbarOrientation { HorizontalScrollbar, VerticalScrollbar };

enum ScrollbarMode { ScrollbarAuto, ScrollbarAlwaysOff, ScrollbarAlwaysOn };

enum ScrollbarControlSize { RegularScrollbar, SmallScrollbar };

typedef unsigned ScrollbarControlState;

enum ScrollbarControlStateMask {
    ActiveScrollbarState = 1,
    EnabledScrollbarState = 1 << 1,
    PressedScrollbarState = 1 << 2
};

enum ScrollbarPart {
    NoPart = 0,
    BackButtonStartPart = 1,
    ForwardButtonStartPart = 1 << 1,
    BackTrackPart = 1 << 2,
    ThumbPart = 1 << 3,
    ForwardTrackPart = 1 << 4,
    BackButtonEndPart = 1 << 5,
    ForwardButtonEndPart = 1 << 6,
    ScrollbarBGPart = 1 << 7,
    TrackBGPart = 1 << 8,
    AllParts = 0xffffffff
};

enum ScrollbarOverlayStyle {
    ScrollbarOverlayStyleDefault,
    ScrollbarOverlayStyleDark,
    ScrollbarOverlayStyleLight
};

// The result of an attempt to scroll. If didScroll is true, then unusedScrollDelta gives
// the amount of the scroll delta that was not consumed by scrolling. If didScroll is false
// then unusedScrollDelta is zero.
struct ScrollResultOneDimensional {
    STACK_ALLOCATED();
    explicit ScrollResultOneDimensional(bool didScroll)
        : didScroll(didScroll)
        , unusedScrollDelta(0) { }
    ScrollResultOneDimensional(bool didScroll, float unusedScrollDelta)
        : didScroll(didScroll)
        , unusedScrollDelta(unusedScrollDelta) { }

    bool didScroll;
    float unusedScrollDelta;
};

struct ScrollResult {
    STACK_ALLOCATED();
    explicit ScrollResult()
        : didScrollX(false)
        , didScrollY(false)
        , unusedScrollDeltaX(0)
        , unusedScrollDeltaY(0) { }
    ScrollResult(bool didScrollX, bool didScrollY, float unusedScrollDeltaX, float unusedScrollDeltaY)
        : didScrollX(didScrollX)
        , didScrollY(didScrollY)
        , unusedScrollDeltaX(unusedScrollDeltaX)
        , unusedScrollDeltaY(unusedScrollDeltaY) { }

    bool didScroll() { return didScrollX || didScrollY; }

    bool didScrollX;
    bool didScrollY;
    float unusedScrollDeltaX;
    float unusedScrollDeltaY;
};

typedef unsigned ScrollbarControlPartMask;

}

#endif
